OMC KING COBRA 351 5.8 Fuel Pump

[darkarcher]

How would I check to see if my fuel pump is working properly. The engine is a 1993 OMC King Cobra 351. My boat mechanic says he thinks it is the fuel pump. I am wondering if there is a way to test it. I have disconnected the lines and taken the pump out.

When I work the plunger up and down it seems to blow and suck, but I can not tell for sure. I even thought of using a rubber band and a balloon to test it but I am not sure it will be air tight or not. I know that when I disconnect the fuel line at the carb, and turn the engine over no fuel comes out.

Any suggestions?

 

[Ocean 22]

Re: OMC KING COBRA 351 5.8 Fuel Pump

Does your engine have a second fuel pump (electric)? If not check your gas filter to see if you have a clog. i would also check an inline filter if you have one. I am not very familiar with that version of marine engines, but i have been wrenching on muscle cars for 25 years. I hope this helps.

 

[Gary H NC]

Re: OMC KING COBRA 351 5.8 Fuel Pump

Either the pump is bad or the pick up tube in the tank is clogged.
If you turned it over with the fuel line unhooked at the carb it should shoot fuel everywhere.
I got a feeling your mechanic is correct.Pumping it by hand off the engine is not going to tell you much.

Is this the pump?
http://bpi.ebasicpower.com/mm5/merc...wer&Product_Code=CARM6696&Category_Code=ALL4C

 

[darkarcher]

Re: OMC KING COBRA 351 5.8 Fuel Pump

So I could take a hose and run it in a gas can and turn the engine over, if the pump is working it should suck fuel just fine. The filter is clean and fills with fuel.... just no fuel makes it to the carb.

 

[Gary H NC]

Re: OMC KING COBRA 351 5.8 Fuel Pump

If you disconnect the line at the carb you are saying no fuel at that point?

 

[darkarcher]

Re: OMC KING COBRA 351 5.8 Fuel Pump

Yes.

I then disconnect at the fuel pump (same line). Still no fuel.

I am thinking disconnect the main fuel line at the fuel filter and just attach a line that runs to a gas tank. Maybe I could eliminate the pickup as an issue.

Made sense to me but I am so knew at this that I thought I might just throw it out.

 

[darkarcher]

Re: OMC KING COBRA 351 5.8 Fuel Pump

This engine is getting the best of me.

I broke down and took it to the shop, after 3 weeks of them having it, they tell me it is a fuel pump. I was not sold on that thought and after some testing of my own I am pretty damn sure it's not the pump. I almost dropped $200.00 plus labor to get that done.

I am sort of back at square one.

I have a boat that cranks but wont start.

I pulled plug # 1, because its the only one I can get to without standing on my ear. It seems to spark just fine when the engine is cranked. I also pulled the distributor cap and gave it a good cleaning.

I poured about 1/2 cup of fresh gas directly down the carb still no start. Each time I stop cranking it I get a small puff of back fire.

I pulled the carb out and the jets are clean, the carb looks fine over all but I am leaning towards using guaranteedcarburetor.com for $248 plus core charge and shipping and get a brand new carb.

I just dont want summer to get by and not use the boat even once.



Any help is greatly appreciated.